Installed recently at the Rose Fitzgerald Kennedy Greenway, each of these two sleek, backless
benches has a solar panel on one side to provide power to recharge cellphones, a connection to the Internet, and for night lighting. Soon they also will have sensors to detect for air pollution — even telling whether someone nearby is smoking.

All of which is not that obvious to the Greenway visitors invited to use them.

“No one is going to know what they are,” said Quinton Page, 24, who was visiting Boston from California and stopped to take in the new seats.

A few steps away, North End native Rocco Rossi, 76, was curiously eyeing the little crowd gathered around the benches and admitted he, too, was flummoxed.

“I’ve been trying to figure out what that was,” Rossi said. “Do you want me to sit on it?’’

Dubbed the “seat-e,” the benches were designed by a research scientist at the Massachusetts Institute of Technology and two colleagues, and are part of a broader program to embed consumer-usable technology into public places. The inspiration came from trying to solve one of those pressing problems of the smartphone era.

“My phone is always dead,” said Sandra Richter, a visiting scientist at the MIT Media Lab. “It’s really a product made for myself.”

Clearly, other cellphone users in downtown Boston identified with Richter’s frustration. In a three-day period soon after the first seat-e showed up last month, 32 smartphones were plugged into it, totaling about eight hours of charging time.

Suzanne Kreiter/Globe Staff

Stine Borregaard of Denmark examined the workings of a seat-e in Boston on Monday.

“Absolutely I would use it if my phone was dying,” Heather Campisano, a city employee, said as she walked by the benches Monday.

One shortcoming is that the seats only have a USB port; cellphone users will need their power cords to recharge.

Richter’s team expects to install two more by Thanksgiving. (However, they will be removed during winter.) Later versions are expected to include sensors that can measure air quality, as well as know when someone is sitting on them. Richter and her fellow designers are also working on a smartphone app that will locate a seat-e.

The seat is appearing at a time when much of the architecture of urban life is becoming smarter. Solar-powered trash cans tell city workers when it’s time for emptying, parking meters can sense if a space is available, and stoplights can adjust to traffic flow. “There’s this whole transition toward making the streets and sidewalks smarter through technology,” said Kris Carter, an adviser to Mayor Thomas M. Menino.

Carter imagines many ways that the city could use the technology in the seat-e to communicate with the people who plug into them, or mine climate data to better understand environmental issues in different neighborhoods.

That is, once people figure out exactly how to use them. Carter does expect a learning curve. “With any new thing you put on the streetscape, it will take some time for people to warm up to it,” he said.

To remove any doubt, they have the word “seat-e” written across one side. And the top has written instructions, an arrow leading to the charging point, and a scannable barcode for more information.

Richter acknowledged her team is still figuring out how best to present the seats. First up, she said, maybe something as simple as a sign: “Charge your phone here.”